Regarding present perfect appropriate use when spoken

Question

If someone asks you

Hey Indiver! Did you see Star Wars movie last week?

Should I reply

• Yes, I saw the movie. It was quite interesting.

Or

• Yes, I have seen the movie. It was quite interesting.

I find difficulty when speaking. I have to think between past indefinite and present perfect.

I usually use present perfect when I have to use those words like already,just or I know that if some work i have done few minutes back.

Please don't use Grammar rules to explain me. I am not preparing for exam. I want to know what is in your mouth tongue while answering above question's answer. Please don't say as well that we can use either because if you were to answer, you use only one sentence instantaneously. I just want to know why your mouth tongue has spoken in that way.

Answer 1

Simple answer:

If the question is:

Did you see it?

I would generally answer:

Yes, I saw it.

If the question is:

Have you seen it?

I would generally answer:

Yes, I've seen it.

Obligatory footnote:

If the question is:

Did you see it?

Then nobody is going to bat an eye if I answer:

Yes, I've seen it.